GIOD - Database Tests (II)
Caltech Exemplar used as a convenient testbed for Objy multiple-client tests
Initial tests showed instability of lockserver
- subsequently ran lockserver on a different machine
Tested clients running simulated Track reconstruction
- CPU-intensive with modest I/O.
Event level (coarse-grained) parallelism
N = 15 - 210 reconstruction processes evenly distributed in the Exemplar system.
Data in an Objectivity/DB database federation
Objects read with simple read-ahead optimisation layer.
- Performance gain of a factor 2
- Results: Exemplar very well suited for this workload. With two (of four) node filesystems it was possible to utilise 150 processors in parallel with very high efficiency.
- Outlook: expect to utilise all processors with near 100% efficiency when all four filesystems are engaged.
- (Work by Koen Holtman: CHEP’98 paper)